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Patented Apr. 28, 1925.

UNITED STATES GUSTAVE A. MILBR-ADT, OF MCKNIGHT ROAD, MISSOURI.

LADDER.

Application filed June 9, 1924.

To all whom it may concern:

Be it known that I, GUsTAvF. A. WILBRADT, a citizen of the United States of America, residing at McKnight Road, in the county of St. Louis and State of Missouri, have invented certain new and useful Improvements in Ladders, of which the following is a specification.

The object of my invention is to produ'e a ladder which finds a particular adaptability in stores and warehouses where it may be used before walls, shelving, etc. A further object is to provide a roller step ladder which is secured on tracks at its upper and lower ends, the upper track being secured to the ceiling and the lower track to the floor. A still further object is to make a ladder which is positioned on tracks which are substantially parallel to each other and which permits of a facile movement of the ladder on the tracks. In ladders of this type it is highly desirable that the ladder be not derailed in its movement. In order to prevent derailment and to take care of irregularities in the floor or support, I have provided two wheels or rollers for the base of the ladder, which wheels are pivotally secured in such a manner that they will not be derailed when the track on which they ride passes over uneven surfaces. My device can be easily made of few and simple parts that lend themselves readily to multiple production and that may be easily replaced.

lVith these and other objects in View, my invention has relation to certain novel features of construction and arrangement of parts as will be hereinafter more fully described, pointed out in the claims and illustrated in the drawings in which Fig. 1 is a front elevation of my device with the rail of the ladder broken away.

Fig. 2 is a side elevation of my device with the rail similarly broken.

Fig. 3 is a plan view of Fig. 1 with the lnngers not shown.

Fig. 4 is a sectional, plan view along the line -1--4 of Fig. 1.

Fig. 5 is a sectional elevation on the line 5-5 of Fig. 1.

Numeral 5 designates the ceiling or upper support and numerals 6 the hangers which are secured to the ceiling 5 and to which from their depending ends is secured the upper track 7. The hangers 6 are hooked at theirlower ends as best shown in Fig. 2 in order not to obstruct the passage Serial No. 718,684.

of my ladder along the track 7., Numeral 8 designates the wheel frame which has its ends bifurcated forming the prongs 9, 10, 11 and 12. Numerals 13 designate the upper track wheels which are rotatively secured between the prongs by means of the axles 1 1 and 15. frame 8 made integral therewith is suspended the slotted strap 16 which is bent around the track 7 as shown in Figs. 1 and 2. Numeral 17 designates one rail of the ladder having the step or tread 18. The slotted strap 16 is secured to the step 18 by means of a U shaped casting 19 which is placed through the slot of the slotted strap 16 and secured to the step 18 by means of the bolts 20. In order to prevent the. slotted strap 16 from becoming disengaged from the upper track 7, hooks 21 are cast integral. with the slotted strap 16 so that they will partiall y envelope the upper track 7, which track I have shown to be of circular cross section. In order to insure the stability of the slotted strap 16 on the upper track 7, I have also cast integral with the strap 16 lateral fingers 22. It will become evident that in order to place the slotted strap 16 on the upper track 17 that it must he slipped over the end of the upper track 7 Numeral 23 designates the other ladder rail.

As many additional steps such as 18 may be provided as is necessary and the rails 17 and 23 may be as long as is necessary. .Numeral 24: designates the floor on which is secured the lower track 25. At the lower ends of the rails 17 and 23 are integrally formed the cars 26, in the center of which are formed holes through which the shaft 27 passes and is secured at each end. The carriage 28 is formed of a block 29 which is jou'rnaled to the shaft 27 by means of the split journal box 30, the lower half of the journal being formed in the block and the other half being formed by a strap 31 having an arcuated projection in its center. This strap is secured to the block 29 by means of the bolts 32. At the front and rear ends of the carriage 28 are secured the casters 33 by means of the bolts 34. These casters are bifurcated as best shown in Fig. 2. Near the end of the prongs of the bifurcated portion-through holes formed therein are positioned the axles 34 on which between the prongs are rotatively secured the dished wheels 35. Spacing nuts 36 are positioned on the axles 34: between the dished From the center of the wheel April 28, 1925.

W. A. MORRELL TWO-CYCLE GAS ENGINE Filed'Jan. 26 1924 

